1 /*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "PublicVolume.h"
18 #include "Utils.h"
19 #include "VolumeManager.h"
20 #include "fs/Exfat.h"
21 #include "fs/Vfat.h"
22
23 #include <android-base/stringprintf.h>
24 #include <android-base/logging.h>
25 #include <cutils/fs.h>
26 #include <private/android_filesystem_config.h>
27 #include <utils/Timers.h>
28
29 #include <fcntl.h>
30 #include <stdlib.h>
31 #include <sys/mount.h>
32 #include <sys/stat.h>
33 #include <sys/types.h>
34 #include <sys/sysmacros.h>
35 #include <sys/wait.h>
36
37 using android::base::StringPrintf;
38
39 namespace android {
40 namespace vold {
41
42 static const char* kFusePath = "/system/bin/sdcard";
43
44 static const char* kAsecPath = "/mnt/secure/asec";
45
PublicVolume(dev_t device)46 PublicVolume::PublicVolume(dev_t device) :
47 VolumeBase(Type::kPublic), mDevice(device), mFusePid(0) {
48 setId(StringPrintf("public:%u,%u", major(device), minor(device)));
49 mDevPath = StringPrintf("/dev/block/vold/%s", getId().c_str());
50 }
51
~PublicVolume()52 PublicVolume::~PublicVolume() {
53 }
54
readMetadata()55 status_t PublicVolume::readMetadata() {
56 status_t res = ReadMetadataUntrusted(mDevPath, &mFsType, &mFsUuid, &mFsLabel);
57
58 auto listener = getListener();
59 if (listener) listener->onVolumeMetadataChanged(getId(), mFsType, mFsUuid, mFsLabel);
60
61 return res;
62 }
63
initAsecStage()64 status_t PublicVolume::initAsecStage() {
65 std::string legacyPath(mRawPath + "/android_secure");
66 std::string securePath(mRawPath + "/.android_secure");
67
68 // Recover legacy secure path
69 if (!access(legacyPath.c_str(), R_OK | X_OK)
70 && access(securePath.c_str(), R_OK | X_OK)) {
71 if (rename(legacyPath.c_str(), securePath.c_str())) {
72 PLOG(WARNING) << getId() << " failed to rename legacy ASEC dir";
73 }
74 }
75
76 if (TEMP_FAILURE_RETRY(mkdir(securePath.c_str(), 0700))) {
77 if (errno != EEXIST) {
78 PLOG(WARNING) << getId() << " creating ASEC stage failed";
79 return -errno;
80 }
81 }
82
83 BindMount(securePath, kAsecPath);
84
85 return OK;
86 }
87
doCreate()88 status_t PublicVolume::doCreate() {
89 return CreateDeviceNode(mDevPath, mDevice);
90 }
91
doDestroy()92 status_t PublicVolume::doDestroy() {
93 return DestroyDeviceNode(mDevPath);
94 }
95
doMount()96 status_t PublicVolume::doMount() {
97 readMetadata();
98
99 if (mFsType == "vfat" && vfat::IsSupported()) {
100 if (vfat::Check(mDevPath)) {
101 LOG(ERROR) << getId() << " failed filesystem check";
102 return -EIO;
103 }
104 } else if (mFsType == "exfat" && exfat::IsSupported()) {
105 if (exfat::Check(mDevPath)) {
106 LOG(ERROR) << getId() << " failed filesystem check";
107 return -EIO;
108 }
109 } else {
110 LOG(ERROR) << getId() << " unsupported filesystem " << mFsType;
111 return -EIO;
112 }
113
114 // Use UUID as stable name, if available
115 std::string stableName = getId();
116 if (!mFsUuid.empty()) {
117 stableName = mFsUuid;
118 }
119
120 mRawPath = StringPrintf("/mnt/media_rw/%s", stableName.c_str());
121
122 mFuseDefault = StringPrintf("/mnt/runtime/default/%s", stableName.c_str());
123 mFuseRead = StringPrintf("/mnt/runtime/read/%s", stableName.c_str());
124 mFuseWrite = StringPrintf("/mnt/runtime/write/%s", stableName.c_str());
125
126 setInternalPath(mRawPath);
127 if (getMountFlags() & MountFlags::kVisible) {
128 setPath(StringPrintf("/storage/%s", stableName.c_str()));
129 } else {
130 setPath(mRawPath);
131 }
132
133 if (fs_prepare_dir(mRawPath.c_str(), 0700, AID_ROOT, AID_ROOT)) {
134 PLOG(ERROR) << getId() << " failed to create mount points";
135 return -errno;
136 }
137
138 if (mFsType == "vfat") {
139 if (vfat::Mount(mDevPath, mRawPath, false, false, false, AID_MEDIA_RW, AID_MEDIA_RW, 0007,
140 true)) {
141 PLOG(ERROR) << getId() << " failed to mount " << mDevPath;
142 return -EIO;
143 }
144 } else if (mFsType == "exfat") {
145 if (exfat::Mount(mDevPath, mRawPath, AID_MEDIA_RW, AID_MEDIA_RW, 0007)) {
146 PLOG(ERROR) << getId() << " failed to mount " << mDevPath;
147 return -EIO;
148 }
149 }
150
151 if (getMountFlags() & MountFlags::kPrimary) {
152 initAsecStage();
153 }
154
155 if (!(getMountFlags() & MountFlags::kVisible)) {
156 // Not visible to apps, so no need to spin up FUSE
157 return OK;
158 }
159
160 if (fs_prepare_dir(mFuseDefault.c_str(), 0700, AID_ROOT, AID_ROOT) ||
161 fs_prepare_dir(mFuseRead.c_str(), 0700, AID_ROOT, AID_ROOT) ||
162 fs_prepare_dir(mFuseWrite.c_str(), 0700, AID_ROOT, AID_ROOT)) {
163 PLOG(ERROR) << getId() << " failed to create FUSE mount points";
164 return -errno;
165 }
166
167 dev_t before = GetDevice(mFuseWrite);
168
169 if (!(mFusePid = fork())) {
170 if (getMountFlags() & MountFlags::kPrimary) {
171 if (execl(kFusePath, kFusePath,
172 "-u", "1023", // AID_MEDIA_RW
173 "-g", "1023", // AID_MEDIA_RW
174 "-U", std::to_string(getMountUserId()).c_str(),
175 "-w",
176 mRawPath.c_str(),
177 stableName.c_str(),
178 NULL)) {
179 PLOG(ERROR) << "Failed to exec";
180 }
181 } else {
182 if (execl(kFusePath, kFusePath,
183 "-u", "1023", // AID_MEDIA_RW
184 "-g", "1023", // AID_MEDIA_RW
185 "-U", std::to_string(getMountUserId()).c_str(),
186 mRawPath.c_str(),
187 stableName.c_str(),
188 NULL)) {
189 PLOG(ERROR) << "Failed to exec";
190 }
191 }
192
193 LOG(ERROR) << "FUSE exiting";
194 _exit(1);
195 }
196
197 if (mFusePid == -1) {
198 PLOG(ERROR) << getId() << " failed to fork";
199 return -errno;
200 }
201
202 nsecs_t start = systemTime(SYSTEM_TIME_BOOTTIME);
203 while (before == GetDevice(mFuseWrite)) {
204 LOG(VERBOSE) << "Waiting for FUSE to spin up...";
205 usleep(50000); // 50ms
206
207 nsecs_t now = systemTime(SYSTEM_TIME_BOOTTIME);
208 if (nanoseconds_to_milliseconds(now - start) > 5000) {
209 LOG(WARNING) << "Timed out while waiting for FUSE to spin up";
210 return -ETIMEDOUT;
211 }
212 }
213 /* sdcardfs will have exited already. FUSE will still be running */
214 if (TEMP_FAILURE_RETRY(waitpid(mFusePid, nullptr, WNOHANG)) == mFusePid)
215 mFusePid = 0;
216
217 return OK;
218 }
219
doUnmount()220 status_t PublicVolume::doUnmount() {
221 // Unmount the storage before we kill the FUSE process. If we kill
222 // the FUSE process first, most file system operations will return
223 // ENOTCONN until the unmount completes. This is an exotic and unusual
224 // error code and might cause broken behaviour in applications.
225 KillProcessesUsingPath(getPath());
226
227 ForceUnmount(kAsecPath);
228
229 ForceUnmount(mFuseDefault);
230 ForceUnmount(mFuseRead);
231 ForceUnmount(mFuseWrite);
232 ForceUnmount(mRawPath);
233
234 if (mFusePid > 0) {
235 kill(mFusePid, SIGTERM);
236 TEMP_FAILURE_RETRY(waitpid(mFusePid, nullptr, 0));
237 mFusePid = 0;
238 }
239
240 rmdir(mFuseDefault.c_str());
241 rmdir(mFuseRead.c_str());
242 rmdir(mFuseWrite.c_str());
243 rmdir(mRawPath.c_str());
244
245 mFuseDefault.clear();
246 mFuseRead.clear();
247 mFuseWrite.clear();
248 mRawPath.clear();
249
250 return OK;
251 }
252
doFormat(const std::string & fsType)253 status_t PublicVolume::doFormat(const std::string& fsType) {
254 if ((fsType == "vfat" || fsType == "auto") && vfat::IsSupported()) {
255 if (WipeBlockDevice(mDevPath) != OK) {
256 LOG(WARNING) << getId() << " failed to wipe";
257 }
258 if (vfat::Format(mDevPath, 0)) {
259 LOG(ERROR) << getId() << " failed to format";
260 return -errno;
261 }
262 } else if ((fsType == "exfat" || fsType == "auto") && exfat::IsSupported()) {
263 if (WipeBlockDevice(mDevPath) != OK) {
264 LOG(WARNING) << getId() << " failed to wipe";
265 }
266 if (exfat::Format(mDevPath)) {
267 LOG(ERROR) << getId() << " failed to format";
268 return -errno;
269 }
270 } else {
271 LOG(ERROR) << "Unsupported filesystem " << fsType;
272 return -EINVAL;
273 }
274
275 return OK;
276 }
277
278 } // namespace vold
279 } // namespace android
280